1. Field of the Invention
This invention relates to installing a length of cable in ducting from a location intermediate the ends of the ducting. The invention is particularly, although not exclusively, applicable to installing optical fibre cables comprising at least one optical fibre unit disposed within an extruded sheath, the or each unit comprising a plurality of optical fibres.
2. Description of the Related Art
Heretofore, lengths of such optical fibre cables have been installed in ducting from locations intermediate the ducting ends by coiling the cable on a drum, transporting the drum to the location, mounting the drum for rotation about its axis for paying cable off the drum, rotating the drum and feeding the length of the cable into a first portion of the ducting extending from said location until the cable is installed in that portion, thereafter feeding the remainder of the cable onto the ground, locating the end of the cable and feeding the remainder of the cable into a second portion of the ducting extending from said location.
This known installation method has two main disadvantages. Firstly, the rotating drum presents a safety hazard both to installation operatives and members of the public when the location is in a public place. In this connection a typical drum rotational speed when installing optical fibre cables is 50 r.p.m. Secondly the feeding of the cable onto the ground can result in damage to the cable and additionally represents a safety hazard.
An object of the invention is to enable the above two disadvantages to be overcome.
This is broadly achieved by a method of installing a cable in ducting from a location intermediate the ends of the ducting, comprising providing the cable in a coil at the location, passing cable from one end of the coil into a first portion of the ducting extending from the location to one end of the ducting and passing cable from the other end of the coil into a second portion of the ducting extending from the location to the other end of the ducting. As will be appreciated the coil of cable does not rotate in this method and the cable is fed from the coil directly into both ducting portions.
The invention also includes apparatus for use in installing a length of cable in ducting from a location intermediate the ends of said ducting, said apparatus comprising: a generally cylindrical housing for housing the length of cable in a coiled condition, said housing comprising respective end walls removably mounted relative to opposite end portions of a generally cylindrical side wall; and a support means supporting said housing for pivotal movement about an axis transverse to the axis of the housing between a first position in which a first one of said opposite end portions is uppermost and a second position in which the second one of said opposite end portions is uppermost.
The invention also includes a method of installing a cable in ducting from a location intermediate the ends of said ducting using an apparatus as defined in the last preceding paragraph and comprising:
housing the length of cable to be installed in said housing in a coiled condition;
positioning said apparatus adjacent said location with said housing in said first position;
removing the uppermost end wall from the housing;
locating the end of the cable adjacent the end portion of the housing from which the end wall has been removed;
passing said end and part of the length of cable extending therefrom through said end portion of the housing from which the end wall has been removed and into a first portion of the ducting extending from said location;
remounting the removed end wall to the housing;
pivoting said housing about said axis transverse to the axis of the housing to said second position
removing the now uppermost end wall from the housing;
locating the remaining end of the cable and passing that end and the remaining length of the cable extending therefrom through the end portion of the housing from which the end wall has been removed and into a second portion of the ducting extending from said location.
Advantageously, the length of cable may be fed into said housing at a site remote from said location said apparatus being transported to said location for positioning adjacent said location.
The support means of the apparatus may include a base and opposed stub axles mounted relative to said base and connected to opposed portions of said housing side wall.
The support means may also include means for supporting said housing in said first and second positions, which means may comprise length adjustable supports extending from said base to engage said housing at or adjacent the end portion which is lowermost when said housing is in said first or second position.
The base of the apparatus may be provided with wheels or endless tracks.
A cable guide may be positioned above said housing.
Preferably the end walls are provided with respective hubs which fit one within the other when said end walls are mounted to said opposite end portions of the housing side wall.
Advantageously, the housing side wall is provided with a closable aperture through which cable may pass.
Preferably, the housing side wall and/or the housing end walls comprises bars and/or tubes.